Users of Amazon's cloud-computing services are ignoring basics security practices that AWS spells out when they sign up for eth service, according to German researchers.

Users of Amazon's cloud-computing services are ignoring basics security practices that AWS spells out when they sign up for eth service, according to German researchers.

Amazon offers computing power and storage using its infrastructure via its Web Services division. The flexible platform allows people to quickly roll out services and upgrade or downgrade according to their needs.

Thomas Schneider, a postdoctoral researcher in the System Security Lab of Technische Universität Darmstadt, said on Monday that Amazon's Web Services is so easy to use that a lot of people create virtual machines without following the security guidelines.

In what they termed was the most critical discovery, the researchers found that the private keys used to authenticate with services such as the Elastic Compute Cloud (EC2) or the Simple Storage Service (S3) were publicly published in Amazon Machine Images (AMIs), which are pre-configured operating systems and application software used to create virtual machines.

Those keys shouldn't be there. "They [Customers] just forgot to remove their API keys from machines before publishing," Schneider said.

But the consequences could be expensive: With those keys, an interloper could start up services on EC2 or S3 using the customer's keys and create "virtual infrastructure worth several thousands of dollars per day at the expense of the key holder," according to the researchers.

The researchers looked at some 1,100 AMIs and found another common problem: One-third of those AMIs contained SSH (Secure Shell) host keys or user keys.

SSH is a common tool used to log into and manage a virtual machine. But unless the host key is removed and replaced, every other instance derived from that image will use the same key. This can cause severe security problems, such as the possibility of impersonating the instance and launching phishing attacks.

Some AMIs also contained SSH user keys for root-privileged logins. "Hence, the holder of the corresponding SSH key can login to instances derived from those images with superuser privileges unless the user of the instance becomes aware of this backdoor and manually closes it," according to a technical data sheet on the research.

Among the other data found in the public AMIs were valid SSL (Secure Sockets Layer) certificates and their private keys, the source code of unpublished software products, passwords and personally identifiable information including pictures and notes, they said.

Anyone with a credit card can get access to Amazon Web Services, which would enable a person to look at the public AMIs that the researchers analyzed, Schneider said. Once the problem was evident, Schneider said they contacted Amazon Web Services at the end of April. Amazon acted in a professional way, the researchers said, by notifying those account holders of the security issues.

The study was done by the Center for Advanced Security Research Darmstadt (CASED) and the Fraunhofer Institute for Security in Information Technology (SIT) in Darmstadt, Germany, which both study cloud computing security. Parts of the project were also part of the European Union's "Trustworthy Clouds" or TClouds program.